1. Field of the Invention
The invention relates to a pneumatic pusher, and more particularly to a pneumatic pusher that allows a change of the flow field pressure by controlling an airflow channel in an open and a close state. Accordingly, an object to be discharged can be pushed forward in a pneumatic manner. The pneumatic pusher is primarily applied to the paintball guns. However, it should not be limited thereto.
2. Description of the Related Art
Most of the paintball guns employ a mechanic pusher to control the discharge of the paintball. However, it contains a great number of mechanic components, thereby resulting in the rise of the failure rate. Meanwhile, the discharge speed will be considerably restricted.
The inventor of the present invention has disclosed a “PAINTGUN WITH PENUMATIC FEEDING AND DISCHARGING PROCESS” in U.S. Pat. No. 6,601,780and pub.No:US2005/005924A1 in which the paintballs are discharged in a pneumatic manner for improving the operation safety, reducing the failure rate and increasing the discharge speed.
However, a return spring has to be mounted on a front part of a delivery tube in the above-mentioned disclosure. The return spring is utilized to apply a restoring force to the delivery tube. People make higher and higher demands on the discharge speed of the paintball gun, like twenty paintballs per second. After prolonged service, the return spring will create fatigue in elasticity, thereby resulting in decrease of the discharge speed. However, the pneumatic pushing force acting on the delivery tube remains unchanged. Thus, the reciprocating process of the delivery tube becomes problematic due to mismatch in speed. Accordingly, a smooth and quick discharge process of the paintball gun will be considerably affected.
Meanwhile, the front end of the delivery tube lacks an elastic rubber ring such that the front end of the delivery tube made of metal will be in direct contact with the paint ball and therefore causes an easy burst of the paint ball.
In addition, it is not possible for the aforementioned disclosure to adjust the reciprocating process of a flow-guiding piston within a flow-guiding body and therefore to change the flow field pressure.
In view of the foregoing shortcomings of the prior art, the inventor of the present invention conducted extensive experiments and tests to overcome the shortcomings and to achieve the desired discharge speed.